I would say there is a lot more to get from this than simply to carry on body. On body carry would have been useless to this fellow, and probably also for the woman. I don't know of anyone who can draw from concealment fast enough to stop someone sucker punching you at fist distance. If you or someone you know has this ability, please drop me a line -- I'd love to do some training with such a person.

Other tools -- skills and training in empty-hand techniques -- are needed, as well as keen awareness skills and the willingness to act on the "something here isn't right" feeling even if that action doesn't fit with typical social norms.

Or simply don't let strangers get that close to you (and split to cover the sidewalk!!!) without your alarm bells ringing like crazy.

If it isn't super crowded and you are within arm's reach of me, I will either back away from you or turn and face you with my thumb under my shirt.... No way I just keep walking in that situation. Yesh.

Active Self Protection has several videos in this vein on YouTube. Craig Douglas (a/k/a “SouthNarc”) of http://ShivWorks.com has training and videos on managing unknown contacts. Even if one has significant empty-handed skills, letting the threat get too close makes it hard to counter.